diff --git a/include/ppu.h b/include/ppu.h
index 69605c5..101949f 100644
--- a/include/ppu.h
+++ b/include/ppu.h
@@ -2,10 +2,10 @@
 
 #include <common.h>
 
-static const LINES_PER_FRAME = 154;
-static const TICKS_PER_LINE = 456;
-static const YRES = 144;
-static const XRES = 160;
+static const int LINES_PER_FRAME = 154;
+static const int TICKS_PER_LINE = 456;
+static const int YRES = 144;
+static const int XRES = 160;
 
 typedef struct {
     u8 y;